The Battle of Callinicum took place on the Easter day (19 April) of 531, between the armies of the Eastern Roman Empire under Belisarius and the Sassanid Persians under Azarethes. After a defeat at the Battle of Dara in 530, the Sassanids moved to take Syria in an attempt to turn the tide of the war. In April 531, a Persian force under Azarethes, numbering about 15,000 cavalry, with an additional group of 5,000 Lakhmid Arabs, crossed the frontier at Circesium on the Euphrates and marched north. As they neared Callinicum, Romans followed them advance westwards. Byzantine forces consisted of about 5,000 men and another 3,000 Ghassanid Arab allies, for the remainder of the army had been left to secure Dara. The Byzantines finally blocked the Persian advance at Chalcis, where reinforcements under Hermogenes also arrived, bringing the Byzantine force to some 20,000 men. The Persians were forced to withdraw, and the Byzantines followed them east.The two armies met outside Callinicum on Apr, 19, 531. For much of the day, the battle was a stalemate, with the Persians and Byzantines trading arrows and cavalry charges. In the afternoon, a squadron of elite Savaran broke through the Roman right flank with surprising force such that the Ghassanids deserted. With their right flank gone; Romans retreated soon finding themselves pressed against the river. Many fleeing Romans jumped into the Euphrates, but some of them including Belisarius managed to escape.The direct outcome of the battle was something of a stalemate; the Byzantine army had lost many soldiers and wouldn't be in fighting condition for months.In fact, the Persian losses were so severe that on their return to the capital, Emperor Kavadh 1st dismissed General Azarethes from command due to his failure in the proceeding with the campaign.This disastrous outcome against the Sassanid army led Byzantine to pay heavy tributes in exchange for a peace treaty and the remaining Byzantine land still in Persian hands.The Eternal Peace agreement between the two empires was signed in summer 532.